This invention relates to an article, system and method used for creating a solid immersion lens array.
Recent advances in optics provide for a method of image capture on a length scale much smaller than previously realized. Such near-field optical methods are realized by placing an aperture or a lens in close proximity to the surface of the sample to be imaged. Others (see, for example, the review by Q. Wu, L. Ghislain, and V. B. Elings, Proc. IEEE (2000), 88(9), pg. 1491-1498) have developed means of exposure by the use of the solid immersion lens (SIL).
Typically special methods for positioning control of the aperture or lens are required, as the distance between the optical elements (aperture or lens) and the sample is extremely small. The SIL is positioned within approximately 0.5 micrometer of the target surface by the use of special nano-positioning technology. SIL technology offers the advantage that the lens provides a true image capture capability. For example, features in a real object can be faithfully captured in an image of reduced spatial extent. In the case of the SIL, features can be captured much smaller than the feature size achievable through the use of conventional or classical optics. Such conventional optics are said to be diffraction-limited because the size of the smallest discemable feature in an image is limited by the physical diffraction.
Due to limitations on resolutions obtainable with conventional optical lenses for the application such as microscopy, techniques have been developed to decrease the Rayleigh limit on transverse resolution xcex4. The Rayleigh limit is given by (xcex4=0.82xcex/(NA) where xcex is the wavelength and NA is the numerical aperture of the focusing objective (NA=n sin (xcex8), where n is refractive index of the medium, and xcex8 is the angle between the outer most rays focusing on the sample and the optical axis).
Coherent light such as laser light can be used to precisely control the wavelength of the illumination xcex. One way to decrease the transverse resolution is to increase the index of refraction of the optical medium, such as by the use of oil-immersion microscopy or use of a solid immersion lens (SIL).
If an SIL is placed in contact with the sample under examination, illumination can be more readily focused on it, and use of the high NA of the system allows efficient collection of the excitation light with high optical transmission efficiency and observation of the sample with very high resolution.
Methods for molding a single solid immersion lens as part of a cover slide are disclosed in U.S. Pat. No. 6,301,055. Illumination of a limited field of view within a single flow channel of sample material is described.
The problem is that a single solid immersion lens mounted on a microscope or attached as an integral part of a slide cover limits the area of view of the sample to a single location, the area directly beneath the solid immersion lens.
Guerra et al. discloses in U.S. Pat. No. 5,910,940 a storage medium having a layer of micro-optical lenses, each lens generating an evanescent field. They further describe in U.S. Pat. No. 6,094,413 optical recording systems that take advantage of near field optics. Though recording of data is possible, the type of lenticular arrays described produce an oblong or otherwise deformed or unsymmetrical pattern unsuitable for microscopy applications.
In accordance with one aspect of the present invention there is provided a method of making a solid immersion lens device having a plurality of solid immersion lenses, comprising the steps of:
providing the plurality of solid immersion lenses in a predetermined pattern; and
securing the solid immersion lenses in the predetermined pattern so as to cause them to be in a fixed position with respect to each other.
In accordance with yet another aspect of the present invention there is provided a solid immersion lens device comprising:
a plurality of solid immersion lenses; and
a body portion in which the plurality of solid immersion lenses are integrally secured, the body portion having a top surface designed to engage a sample for viewing of the sample through the plurality of solid immersion lenses.
In accordance with yet another aspect of the present invention there is provided a cover slide having a plurality of solid immersion lenses integrally formed therein, the cover slide having a surface designed to engage a sample for viewing of the sample through the plurality of solid immersion lenses.
In accordance with still another aspect of the present invention there is provided a cover slide having a plurality of solid immersion lenses integrally formed therein, the cover slide having a surface designed to engage a sample for viewing of the sample through the plurality of solid immersion lenses and an open viewing area designed to engage a sample for viewing of the sample using a microscope under normal magnification.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims and by reference to the accompanying drawings.